As the July 31 MLB trade deadline approaches, teams have begun to make clearer decisions between acting as buyers or sellers. With several organizations taking a 2015-first approach in recent days, the available talent on the market has begun to swell.

There has been a more proactive approach this year, with several teams striking early and consequently forcing the hands of their competitors. So after years of deadline duds, the sellers' market that has emerged could result in some highly consequential action.

For all rumors surrounding some of the biggest names on the market, check out the latest buzz below.

Lester Heading West?

After trading Jake Peavy to the San Francisco Giants last week, the Boston Red Sox could be sending another veteran starter to the NL West. Longtime Sox ace Jon Lester has had a sterling campaign, and according to ESPN's Buster Olney, the Los Angeles Dodgers have emerged as the favorites for Lester:

The 30-year-old southpaw is on pace to set career-bests in ERA, FIP and xFIP and has increased his strikeout rate to its highest marks since 2010. After shouldering a huge burden in carrying Boston through the postseason in 2013, Lester has piggybacked off that success and re-established himself as a true ace after a couple of rocky seasons.

There had been rumors surrounding Matt Kemp as a potential centerpiece for a Lester deal, but The Boston Globe's Nick Cafardo shot down those rumblings later:

Indeed, for a Red Sox team with a loaded farm system, sending Lester away could be an opportunity to accelerate their return to contenders. Given Boston's outfield woes, Dodgers prospect Joc Pederson might be part of the Red Sox's request, though Los Angeles has been slow to make Pederson available.

Similar to the David Price rumors, the Dodgers acquiring Lester might seem like overkill. With Clayton Kershaw and Zack Greinke in tow, few can match the top of Los Angeles' rotation. Lester would certainly upgrade the postseason pitching staff, but the Dodgers are likely at the top of the heap already.

With Lester set to hit free agency this winter, the Red Sox could cash in before potentially losing him to a mega-contract offer. Given the fireworks these two teams engaged in during the 2012 season, it would be wise to keep track of developments between them.

Zobrist to Giants?

Though the Rays have caught fire of late, they remain 7.5 games out of the AL East lead, with five teams to leapfrog for the second wild-card spot as well. As such, the likes of Price and Ben Zobrist could remain on the block over the next few days. The Giants are apparently among the teams interested in the latter:

San Francisco's desire for Zobrist makes sense. On a park-adjusted basis, the Giants' second basemen rank 26th in hitting. The likes of Brandon Hicks and Ehire Adrianza have failed to produce, and Marco Scutaro is on the disabled list. The versatile Zobrist would provide a much-needed upgrade in the middle infield.

But the Giants farm system was already relatively weak, and they traded two of their top prospects for Peavy, according to ESPN's Keith Law (subscription required). The Rays have been consistent in demanding exorbitant prices for Zobrist and Price, so pitcher Kyle Crick and/or catcher Andrew Susac would likely open the discussion.

San Francisco may be all in to capture their third championship in the past five years, however. Crick might be untouchable, and someone like shortstop Christian Arroyo might be a more centerpiece. Regardless, it's clear an NL West arms race between the Giants and the Dodgers has started.

Hamels Moving?

The Phillies' window of contention has quite clearly passed, as they are floundering in the NL East basement and on the verge of missing the postseason for the third straight year. Nonetheless, according to Cafardo, Philadelphia general manager Ruben Amaro, Jr. remains ambivalent about shedding his veteran stars, including ace starter Cole Hamels:

The Phillies have been wishy-washy on whether they will make lefthander Cole Hamels available. Hamels could land the biggest haul if the Phillies are serious about rebuilding their farm system, then using the $90 million savings on signing mid-range free agents.

The Phillies want four or five prospects for Hamels (I wrote three last week and was told by a Phillies official I was too conservative) and it doesn’t appear anyone would pay that type of bounty. Around the industry, the Phillies are being perceived as asking too much for their players. The Phillies are saying “make us a fair deal.”

Considering that Philadelphia's farm system is barren after years of win-now trades, failing to restock the minors would appear fallacious. The Phillies are apparently doing their due diligence, though, as scouts were spotted in Portland, Maine for the Red Sox Double-A squad:

If the Sox trade Lester as hinted above, they could potentially replace his hole in the rotation with Hamels. Boston's top pitching prospect, lefty Henry Owens, is in Portland, though he would seemingly be untouchable. Catcher Blake Swihart could also be a target for the Phils, as Fangraphs recently named the 22-year-old the best backstop in the minors.

Moving Hamels would represent a refreshingly rational self-evaluation from the Phillies. If they can extract a top prospect like Owens or Swihart, they could start acquiring the cornerstones for their next World Series contender.